1. Field
Embodiments of the present invention relate to a sealing member for a master cylinder, and more particularly to, a sealing member for a master cylinder capable of minimizing a phenomenon of non-generation of brake pressure due to invasion of foreign materials.
2. Description of the Related Art
In general, a master cylinder is a device to generate hydraulic pressure in a hydraulic brake system.
A master cylinder includes a cylinder body in which a bore is defined, and a piston installed in the bore so as to be advanced or retracted in the bore. A sealing member is installed to the cylinder body to form a hydraulic pressure chamber in which a pressure necessary for braking operation is generated according to advance and retreat of the piston. The piston is formed with communication holes so that liquid may move among a hydraulic pressure chamber, an oil tank and a wheel brake. When the piston is advanced, the communication holes are displaced farther forward than the sealing member, and the liquid in the hydraulic pressure chamber is pressurized, thereby generating brake pressure. On the contrary, when the piston is retracted, the communication holes are displaced farther rearward than the sealing member, and the liquid in the hydraulic pressure chamber is returned to the oil tank, thereby releasing brake pressure.
The sealing member is formed in a ring shape and is fitted in a receiving recess of the cylinder body. The sealing member is referred to as a “cup seal” because of a cup-shaped cross sectional shape thereof.